Late Toxicities in Pediatric Cancer Care

“Considering the frequency of both pediatric cancer survivorship and of late toxicities related to treatment, childhood cancer is often the cancer diagnosis that lasts a lifetime,” said Kerry Parsons, PharmD, at the recent Hematology/Oncology Pharmacy Association annual conference.

“We always have to think about the toxicities that we’ve introduced into these patients, and how we can try to prevent them or clean them up after that,” she said.

Childhood Cancer Facts
New diagnoses of pediatric cancer (young children and adolescent populations) represent 1% of all newly diagnosed cancers across the United States population, or about 20,000 new cases per year, stated Parsons, a pediatric hematology/oncology pharmacist at Children’s of Alabama in Birmingham.

In young children, about half of malignancies are represented by acute lymphoblastic leukemia and brain tumors, at 26% and 21%, respectively. In adolescents up to age 19, there is much more variability. In that population, Hodgkin lymphoma is the most frequently occurring cancer, and brain tumors are still in the top one-third of malignancies, said Parsons.

“We also notice an emergence in what we might typically consider to be adult cancers,” she said, especially thyroid cancer and melanoma.

Late Toxicities in Patients with Childhood Cancer

“Risk factors for late effects in childhood cancer survivors are variable, but commonsensical based on what we know about toxicities,” said Parsons.

More than 60% experience at least one late effect while 27% experience a late effect that is severe or life threatening. Risk factors are related to the type and location of the cancer, the area of the body treated, genetics, and the child’s age when treated.

Cardiovascular effects are most often correlated with exposure to radiation and anthracyclines. Incidence of secondary malignant neoplasms within the first 20 to 30 years after diagnosis ranges from 3% to 21%, and is associated with factors such as radiation and high-risk chemotherapy exposure. Endocrine disorders are seen in 40% to 60% of patients treated for cancer in childhood.

“Cognitive effects are a persistent deficit in childhood cancer survivors,” Parsons stated. “Deficits will vary significantly based on the underlying diagnosis for the patient, and these effects are associated with the survivor’s ability to hold a job, achieve at least a median level of education, and to be able to live independently of their parents.”

Obstacles to Survivorship Care

“Lifestyle behaviors are going to contribute to some of the late toxicities that we’ve observed in childhood cancer survivors,” Parsons noted. These behaviors include regular tobacco use, heavy alcohol consumption, lack of physical activity, and lack of healthcare utilization.

“Any pediatric cancer patient across the board has about a 75% chance of long-term survival,” she said. “We had over 80% survival in the most recent decade across all cancer diagnoses, and this is a testament to the multi-institutional cooperative group research efforts across the nation and even across the globe. The mission to better understand childhood cancer survivorship is very much alive and well.”